Steam superheater and method of controlling superheat



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STEAM SUPERHEATER AND METHOD OF CONTROLLING SUPERHEAT Filed March 7, 1944 5 Sheets-Sheet 2 March 8, 1949. F. w. LINAKER STEAM SUPERHEATER AND'METHOD OF CONTROLLING SUPERHEAT 5 Sheets-Sheet 3 Filed March 7, 1944 DIS RIBUTOR a A w ,W J 5 a; u 0 m M w fi A: m f 4 If a s m w o o f s a M u A A K u" E n E w 5 S W;

SUPER HIATID COIL PRE'SUPE H HEATER CON-S INVENTOR.

DISTRIBUTOR H N m T T A March 1949- F. w. LINAKER STEAM SUPERHEATER AND METHOD OF CONTROLLING SUPERHEAT 5 Sheets-Sheet 4 Filed larch 7, 1944 Stun. O HL-(K 3P3 Mamh 1949- F. w. LINAKER 2,463,888

STE SUPERHEATER AND METHOD I -OF CONTROLLING SUPERHEAT Filed llarch.7, 1944 5 Sheets$heet 5 FREDERICK WLINAKER A -fir I Patented Mar. 8, 1949 UNITED STATES PATENT OFFICE- STEAM SUPERHEATER AND METHOD OF CONTROLLING SUPEBHEAT Frederick W. Linaker, Forest Hills, N. Y.

Application March 7, 1944, Serial No. 525, 334

6 Claims. (01. 122-479) This invention relates to steam superheaters, and also to methods of controlling the tempem ture of the superheated steam, and provides improvements therein.

In a boiler combination comprising steamgenerating elements and steam superheating elements, the present invention provides a novel combination and arrangement by which improved results are obtained. The invention provides improved results in the control of the temperature of the superheated steam delivered by the superheater and in the protection of the superheater element from over-heating. It provides for delivery of superheated steam at approximately a desired predetermined temperature, under variations of steam delivery and fuel consumption.

The invention may be applied to boiler combinations in which the heating of the super heater element is done by convection, by radiation, or by a combination of convection and radiant heat.

Several embodiments of the invention are illustrated in the accompanying drawings. The drawings also illustrate several forms of apparatus in which the method of the invention may be carried out. The apparatus invention, however, may receive other embodiments than those herein specifically illustrated and described.

In said drawings Figs. 1-5 illustrate one embodiment;

Fig. 1 being a vertical sectional view through a steam boiler, showing so much thereof for those skilled in the art as is necessary to illustrate the invention;

Fig. 2 is a plan view looking down on the superheater elements, headers and distributor seen at the upper right-hand part of Fig. 1;

Fig. 3 is a vertical sectional view through the distributor;

Fig. 4 is a front elevation of a distributor; and

Fig. 5 is a view in side elevation of a distributor.

Fig. 6 illustrates another embodiment of the invention, which includes a pre-superheater, shown at the left side of the figure;

Figs. 7, 8 and 9 are views illustrating a diiferent embodiment of distributor from that illustrated in Figs. 3, 4 and 5;

Fig. 7 being a vertical sectional view;

Fig. 8 a front elevation; and

Fig. 9 being a view in side elevation, with the pipes shown in the other figures omitted.

Fig. 10 is a view similar to Fig. 2 illustrating an embodiment comprising a plurality of distributors (36, 35A).

The boiler is fired by any suitable means (not 7 shown). A boiler of the water-tube type has been shown by way of illustration. The tubes may have any suitable or known arrangement. Suitable baflles for controlling the flow of the combustion gases with relationto the tubes may be provided. Vertical baffles 3 and 4 and transverse baffles 5 are illustrated.

Sets of vertical water-tubes 3 and 9 are illustrated, connected at the lower ends thereof to a water-drum HI and at the upper ends thereof to a steam-drum i2. Other sets of water-tubes, such as 1, connected with water-drum l0 and steam-drum II, are provided, according to the design of the boiler. The sets of water-tubes I are connected at the lower ends thereof to waterdrum Ill and at the upper ends thereof to steam-drum l8. Steam from drum l2 flows to drum I! through a pipe or pipes I3. Other sets of water-tubes I 4 and IS in another part of the boiler are shown.

Numeral 25 designates the superheater part, which is in the form of a set of superheater tubes or elements. These tubes or elements are usually, and as here shown, coiled. Some of the superheater tubes or elements 25 are divided into serial sections, here shown as two, a section 21 and a section 23. The superheater tubes or elements which are not divided into-sections are connected at one end to an inlet-header or receiver 3|, and at the other end thereof to an outlet-header or receiver 33. The tubes of section 21 are connected at one end to the inlet-header 3| and at the other end to a distributor 35, and the tubes of section 23 are connected at one end to the distributor 35 and at the other end to the outlet-header 33. A plurality of these distributors 35, 35A may be provided, if desired, and as illustrated in Fig. 10, thedistributors may be operated at diflerent temperatures so that a full control of the temperature of the superheated steam at the outlet-header 33 may be obtained.

Steam lines 40 are provided from the steamdrum It to the superheater inlet header 3|, and other steam lines 4| are provided from the drum l8 to the distributor 35.

The function of the distributor 35 is to control the flow of saturated steam, so that it flows serially through the two sections 21 and 23 of the superheater coils or elements 25 to the outletheader 33, or in parallel to the outlet-header 33 through each section 21 and 29.

The distributor, 35 may be any suitable valvearrangement, but advantageously has the structure illustrated in Figs. 3 and 4, and comprises a chambered body 45 and headers or branches 41, 48, 49, 50 and 5|. A ported partition 53 is provided between the branches 41 and 48; a ported partition 55 is provided between branches 5!! and 5|; a ported partition 51 is provided between branches 49 and 50, and a solid partition 59 is provided between branches 48 and 49.

The sections 21 and 29 of superheater tubes or elements 25 communicate respectively with branches 50 and 5| of distributor 35. Pipes 56 connect branches 41 and 5| of the distributor. I

Pipes 58 lead from branch 49 to the superheated steam outlet-header 33.

A multiple valve 60, comprising valves 62 and 63, is provided for controlling the ports 53, 55 and 51 of the partitions. A motor for operating the valve 60 may be and as here shown, is incorporated in the distributor. To this end, the multiple-valve 60 is provided with a piston 66 and a cylinder 61 is provided between the partition 59 and another partition 68 in the chamfered body 45. Steam or other suitable fluid for operating piston 66 is admitted to and vented from cylinder 61 through pipes and 1|, and 12 and 13. i

The operation of the multiple-valve 60 of distributor 35 may be manual, but is advantageously done by automatic devices, as illustrated. Referring to Fig. 5, fluid for actuating piston 66 of distributor 35 is admitted to and vented from cylinder 61 through two electrically operated or fluid operated valves of well-known types, such as Brown Instrument Co. diaphragm valves 11 and 18, and a thermostat 80 in the superheater outlet-header 33, acting through any well-known electrical arrangement (not shown), energizes the electrical valves to efiect the operation of the distributor 35. The valves 11 and 18 are twoway valves. Fluid enters valve 11 through a pipe 82 and flows to one side or the other of piston 66 through pipes 10 and 12 in accordance with the position of the valve. Fluid is vented from one side or the other of piston 66 through pipes 1| and 13, valve 18, and a vent-pipe 84 in accordance with the position of valve 18. When valve 11 admits fluid to one side of piston 66, valve 18 operates to close the vent from that side and open the vent from the opposite side and vice versa.

Operation A temperature desired for the superheated steam is determined, and, when automatic means for operating distributor 35 is provided, the thermostat 80 is set at a temperature slightly above the predetermined temperature.

When the superheated steam in outlet-header 33 is at or below the predetermined temperature, the automatic valves 11 and 18 act to put or keep the multiple-valve 60 of distributor 35 in a position in which steam flows serially throughthe sections 21 and 29 of the superheater tubes or elements (position shown in Fig. 3). Saturated steam from drum I8 enters superheater inletheader 3| through pipes 40, then through superheater tube section 21 to branch or part of distributor 35, then into branch 5| through the port in partition and into and through the superheater tube section 29 to superheater outletheader 33. Those ofthe superheater tubes or elements 25 which arenot connected with a distributor, conduct steam directly from intakeheader 3| to outlet-header 33. The number of the superheater tubes or elements which are con- 4 nected to a distributor is governed by engineering design for effecting the desired superheat control for the installation to which the invention is applied.

When the superheated steam in outlet-header 33 rises above the predetermined temperature, the thermostat actuates the valves 11 and 18 to operate the multiple-valve 60 of the distributor 35 so as to position it to control the flow of saturated steam in parallel through the superheater sections 21 and 29, and thereby receive less superheat. The action of the thermostat 80 is to energize valves 11 and 18 so that valve 11 opens pipe 10 to admit fluid to the upper side of piston 50 (and also closes pipe 12), and valve 18 opens pipe 13 leading to vent pipe 84 and closes pipe 1 I. Piston 50 is moved downward with reference to its position shown in Fig. 3, opening the ports in partitions 53 and 51 and closing the port in partitiozi 55.

Saturated steam flows to superheater section 21 and thence to outlet-header 33, from drum l8 through pipes 40, intake-header 3|, superheater tube section 21, branch or part 50 of distributor 35, then to branch 49 through the port in partition 51, and then to the superheater outlet-header 33 through pipes 58. Saturated steam also flows to superheater section 29, and thence to outletheader 33, from drum l8, through pipes 4|, branch or part 49 of distributor 35, then into branch 41 through the port in partition 53, then through pipes 56 into branch or part 5|, and then through the superheater tube section 29 to the outletheader 33.

When the temperature of the superheated steam in outlet-header 33 falls below the predetermined temperature, distributor 35 is again actuated to control the flow of steam through the superheater tube sections 21 and 29 so that the flow is serial.

flow through the superheater tube sections 21 and 29 a predetermined temperature for the superheated steam at the outlet-header 33 is very closely approximated.

In Fig. 6 there is illustrated an embodiment which is advantageous where the volume or temperature of the products of combustion passing over the superheater elements is, at times,

not sufllcient to raise the temperature of the superheated steam to the final degree desired. The embodiment includes a pre-superheater section (in the form of tubes or elements) in a part of the boiler where the temperature is comparatively low. Much of the structure of this embodiment is similar to that of Fig. 1, and similar parts in the two views are designated by the same reference numerals, and the description thereof is not repeated.

Numeral 93 designates a distributor or means for controlling the flow of saturated steam from drum l8 to the inlet-header 3| of the superheater, either directly, or through the presuperheater section 90. The distributor 93 may be any suitable valve arrangement, but advantageously, as shown in the drawings, comprises a chambered body 95 having branches 91, 98, 99. Valves llll, I02 control the communication between the branches, as hereinafter described.

The valves may be manually operated, or be operated through the action of the thermostat 80 and suitable known electrical means, as illustrated in the drawings.

Pipes 40 convey saturated steam from drum l3 to branch 98 of distributor 93. Pipes l05 con- By a succession of operations of distributor 35 to cause serial flow or multiple 2,4es,aea

nect branch I! with the superheater inletheader 3|. The intake ends of pre-superheater elements 90 are connected to branch 8! and the delivery ends to inlet-header 3|.

When the temperature 01' the superheated steam in outlet-header 33 is below a predetermined or desired temperature. the distributor 13 operates (or is operated) to move valve ill to close branch 91 from branch ll and valve II! to open branch II to branch 89. Saturated steam flows from drum ll through pipes 40 to branch 88 of distributor I, then to branch OI, then through the pre-superheater OI to inlet-header 3|. From the superheater inlet-header 3! the flow of steam is controlled by the distributor II in the manner heretofore described in connection with the embodiment of Fig. 1. when the temperature of the steam at outlet-header I3 is such as not to req the additional heat provided by the pre-superheater 9|, the distributor 93 operates by the means previously described (or is operated), to close branch 99 or distributor 93 from branch 98 and open branch II to branch 98. Saturated steam then flows to inlet-header 3| by way of pipes ,branches 9B, 91 and pipes I05.

An embodiment of distributor 35 differing somewhat from that of Figs. 1 to 5 is illustrated in Fig. 6, and in greater detail in Figs. 7, 8 and 9. Parts in Figs. 6 to 9 similar to parts in Figs. 1 to 5 are designated by the same reference numerals, and the description thereof is not repeated. Referring to the Figs. 6 to 9, the valve operating motor is located outside of the chambered body 4! and the provisions constituting the cylinder portion 61 are omitted. In place of disk-type valves, butterfly type valves ilil, iii, and H2 are provided, which have stems H5, Ill, I I1 projecting through the chambered body 45. The valves III, III, II! are operated in any suitable manner; in the illustrated means, the stems have arms I20, III, I22 thereon which are connected to a drag-link I25 through which they act in unison. A suitable motor, as an electromagnetic motor III, or a power cylinder of the well-known Brown Instrument Co. type is provided for operating the valves through the draglink I25. This operation of the motor I21 is under the control of thermostat 80 through suitable electrical connections, as previously stated in reference to Fig. 1.

Modes of procedure in carrying out the method of this invention are apparent from the foregoing description. Briefly stated, saturated steam is superheated in superheater elements, some of which are arranged to operate in series and others of which are arranged to operate either in series or in parallel. When the temperature of the superheated steam in the receiver or outletheader becomes too high, the superheat elements, which are arranged to operate either in series or in parallel, are caused to operate in parallel and thereby reduce the temperature of the superheated steam in the receiver or outlet-header. When the temperature of the superheated steam in the receiver or outlet-header falls too low, the

superheater elements which are arranged to operate either in series or in parallel are caused to operate in series, and hotter steam is delivered to the receiver or outlet-header, thereby raising the temperature of the steam. Control of the temperature of the superheated steam in the receiver or outlet-header is effected by operating certain of the superheater elements either in series or in parallel, alternately. This may be 6 elected by controlling the steam-flow through ,the distributors either by manually controlled v lve r th ou h e i at What'is steam to flow in said second set of elements from said intake to said receiver either serially or in parallel, said means comprising a thermostat at the receiver for superheated steam and motor operated valves operated therefrom opening and closing chambers in said distributor connecting said second set of elements for said operation in series only, when the superheated steam delivered to said receiver does not exceed a predetermined temperature, and opening and closing chambers in said distributor connecting said second set of elements for said operation in parallel when the temperature of the superheated steam in said receiver exceeds the predetermined temperature to deliver superheated steam to said receiver at a temperature below said predetermined temperature, thereby to control the temperature of the superheated steam in said receiver approximately to said predetermined temperature.

2. A steam superheater, according to claim 1, further comprising a second distributor and associated superheater elements, motor operated valves and thermostat, and wherein said thermostat associated with said second distributor is set at a temperature diflerent from the temperature at which the thermostat associated with the first 40' distributor is set to act to control more closely the temperature of the superheated steam in the receiver.

3. A steam superheater comprising a steam intake and a receiver for superheated steam, a set of elements in which steam is superheated always in serial arrangement between said intake and said receiver, another set of superheater elements in which steam may pass either serially or in parallel from said intake to said receiver, a distributor with which said second set of superheater elements is connected intermediate of said elements, a duct for conveying saturated steam directly to said distributor, a duct for conveying superheated steam directly from said distributor to said receiver, and means for actuating said distributor to connect the elements ofv said second set of superheater elements which are connected thereto for said serial operation, when the superheated steam in said receiver does not exceed a predetermined temperature, and when the superheated steam in said receiver is above said predetermined temperature, to connect the part of thesaid second set of superheater elements which is before the distributor with said duct for conveying superheated steam directly to the receiver, and the part oi the second set of superheater elements which is aiter the distributor with said duct for conveying saturated steam directly to the distributor and thence to the receiver, thereby to control the temperature of the superheated steam in said receiver approximately to said predetermined temperature.

4. A steam superheater according to claim 1, wherein said distributor comprises ported chambers A, B, C, D, E; A being a chamber in com- 7 munication with chamber E and with chamber B through its port; B being a chamber in communication with a supply of saturated steam; C being a chamber in communication with the superheated steam receiver and with chamber D; D being a chamber in communication with chambers C and E through the'ports thereof, and with the delivery end of the part of said second set oi! superheater elements which is before the distributor; and E being a chamber in communication with chamber D through its port and with the intake end of the section of said second set of superheater elements which is after the distributor; a duct conducting saturated steam to said chamber B, a duct connecting chambers A and E, and a duct from chamber to the superheated steam receiver; and valves for closin the 'ports between chambers A and B, and C and D, and opening the port between chambers D and E for said serial connection of said second set of superheater elements to said superheated'steam re ceiver, and, for parallel connection between said second set of superheater elements and said superheated steam receiver, closing the port between chambers D and E and openingpthe ports between chambers A and B and C and D.

5. A steam superheater according to claim 1, wherein said valves are in the form of a multiple valve, and further comprising a motor for moving said multiple valve to its positions for serial and parallel flow respectively.

6. A method of controlling the temperature of superheated steam delivered from steam superheaters comprising conducting saturated steam in series through superheater elements arranged only for series flow and concurrently conducting saturated steam in series through other superheater elements, arranged for either series or parallel flow, while the delivered superheated steam has a temperature which does not exceed a Predetermined temperature, and upon said delivered superheated steam exceeding said predetermined temperature, conducting saturated steam in par,-

allel through said superheater elements arranged oncurrently for either series or parallel flow,

with conducting saturated steam in .series through those of the superheater -e ements ar-,

REFERENCES CITED The following references are of record in the file of this patent:

STATES PATENTS Name Date Jaastad ..-Jan. 30, 1900 Bell June 9, 1925 Jacobus 1 Oct. 28, 1930 Number Armacost Sept. 11, 1934 Heller July 27, 1937 Kerr Oct. 25, 1938 Bailey Apr. 9, 1940 FOREIGN PATENTS Country Date France Apr. 13, 1931 Great Britain Jan. 11, 1934 Number Lucke Feb. '16, 1932' 

